Ordered and nanostructured polymer compositions can be used in a variety of contexts for the production of materials having a number of desirable properties including an ability to form structures having small three dimensional architectures. The material properties of such polymer compositions can be tailored to provide useful materials in a variety of technologies such as those used in photovoltaic systems, photonic crystal systems, nano-porous membrane systems and nanolithographic systems.
Nanostructured materials often are used to refer to materials whose structural elements have dimensions in the 1 nm to about 100 nm range. One particularly useful class of nanostructured materials includes block copolymers. Block copolymers can assemble to form nanoscale domains on a periodic lattice. For example, well ordered block copolymer thin films have been used as templates to pattern microelectronic devices and magnetic storage media, as sacrificial templates for the fabrication of inorganic mesostructured materials and for the preparation of polymeric nanoporous materials. Among the technological challenges for implementing block copolymer directed assembly is the need to achieve well ordered systems using components that do not compromise the operability of the systems in which these materials are implemented.
One approach to producing ordered materials begins with a segregated block copolymer template. In the absence of kinetic limitations, the phase segregation of A-B and A-B-A diblock and triblock copolymers is thermodynamically governed by the product χN where χ is the Flory-Huggins interaction parameter between the two dissimilar blocks and N is the total number of repeat units in all the blocks of the block copolymer. Upon segregation, the morphology is governed primarily by the relative volume fraction of the two blocks although the segregation strength of microphase segregated systems also plays a role near the phase boundaries. While small domain sizes are desirable, a challenge for achieving small domain sizes is that decreases in molar mass required to decrease the inter-domain spacing also weaken the segregation strength.
Methods and/or materials effective in inducing and increasing order and nanostructures in polymeric materials are strongly desired, particularly for polymeric materials used in various industries (e.g. materials used in three dimensional microfabrication technologies such as nanolithography). For this reason, the development of improved polymer compositions and/or lithography methods and systems that can utilize such compositions represents a significant breakthrough in this technical field.